The present disclosure relates to systems and methods for the early detection and characterization of outbreaks of infectious diseases or disorders. Generally, the system may be used for capturing and analyzing web-based patient symptom queries to thereby predict future changes in the incidence of infectious illness in both time and location. Methods to predict the incidence of disease or disorders are also disclosed.
In public health practice, the earliest detection of a disease outbreak offers the best opportunity to mitigate its effects. Consequently, one of the core functions of public health surveillance is to monitor public health status and recognize at the earliest possible time, the appearance of disease or a change in its distribution or incidence. To address that need, various methods of early detection are incorporated throughout the public health infrastructure at all levels from local to national. Depending on the specific microbiological etiology of the outbreak, this early intervention allows for early recognition of affected individuals, initiation of treatment, and initiation of post-exposure mitigations among the exposed population. Accordingly, prediction technologies should offer the earliest reliable detection and characterization of outbreaks to afford the greatest opportunity to minimize causalities.
Traditional systems of public health surveillance, developed and managed by public health agencies at various jurisdictional levels from local to national, fall into two categories: passive and active. Passive systems rely on reporting from community based healthcare personnel, whether from clinical encounters or laboratory identification of select microorganisms. These systems generally under-report infectious disease incidence and prevalence, and are only as timely as the reporters. Recognizing the limitations of the passive systems, public health surveillance authorities have developed active systems that prospectively monitor for the appearance of diseases and pathogens. These systems can identifying the appearance of pathogens in the environment earlier than passive surveillance systems, but are limited still in their scope. However, they are also directed against specific agents and illnesses, and active systems that are based on environmental monitoring have their own inherent time delays between the appearance of a pathogen and its recognition in the surveillance system due to time delays for laboratory analysis.
A substantial number of active surveillance systems have been developed. Some of these systems exploit search engines such as Google and Yahoo. The Internet, more specifically social media, is growing as a resource to gain advice or chat about health conditions. Microblogging sites like Twitter and Facebook or search engines such as Google collect random entries about conditions affecting its users.
The best developed active surveillance system on the national scale is the CDC's system for influenza. It provides a clear picture of the emergence and development of the annual influenza epidemic, but its reports lag the actual changes in influenza incidence by about a week. The reason for the lag is that the system depends on the reporting of medical visits by specific sentinel medical practices, of individuals ill with symptoms compatible with influenza. It requires that individuals become ill enough to request an appointment and wait for that appointment to occur before there is the possibility of a report being generated.
Recognizing the time delays inherent in surveillance systems based on the data generated by clinical visits and the critical importance of detecting the earliest possible evidence of an outbreak, there have been a number of methods proposed to accelerate reporting. Many of these are based on examining information from individuals who may be developing illness, eliminating the additional steps required to seek medical care and generate a medical report. All these techniques exploit one aspect or another of the public's use of the Internet to report or obtain information. Others have used medical query sites maintained by hospitals or health departments, emergency rooms or pharmacy visits.